Go Back   IceInSpace > Equipment > Equipment Discussions
Register FAQ Calendar Today's Posts Search

Reply
 
Thread Tools Rate Thread
  #1  
Old 15-06-2008, 11:04 AM
caleb
Registered User

caleb is offline
 
Join Date: Dec 2007
Location: gosford, australia
Posts: 206
laser mount

how can i mount a laser to my telescope. where can i buy a mount, will anymound do, such as a usual one for a typical 2X finder.
where can i buy, how do i put mount on telescope without drilling etc.
Reply With Quote
  #2  
Old 15-06-2008, 03:05 PM
OneOfOne's Avatar
OneOfOne (Trevor)
Meteor & fossil collector

OneOfOne is offline
 
Join Date: Jul 2005
Location: Bentleigh
Posts: 1,386
I use a Lumicon mount, but I had to drill holes in the tube when I had it on the 8" Newt. When I got the C11 I was able to use some existing mount screws on the tube (whew!). I think either Star or Sirius were making their own, check their site, but I don't know if it needs holes or is double sided tape like the TelRad.
Reply With Quote
  #3  
Old 15-06-2008, 06:27 PM
caleb
Registered User

caleb is offline
 
Join Date: Dec 2007
Location: gosford, australia
Posts: 206
do you have a pic. what laser are you using?
Reply With Quote
  #4  
Old 15-06-2008, 08:10 PM
Starkler's Avatar
Starkler (Geoff)
4000 post club member

Starkler is offline
 
Join Date: Sep 2004
Location: Melbourne
Posts: 4,900
I wish i could buy a laser, but living in Vic.....
Reply With Quote
  #5  
Old 16-06-2008, 08:58 AM
asterisk's Avatar
asterisk (Geoff)
Registered User

asterisk is offline
 
Join Date: Jun 2007
Location: Ruse, Australia
Posts: 232
Quote:
Originally Posted by caleb View Post
how can i mount a laser to my telescope. where can i buy a mount, will anymound do, such as a usual one for a typical 2X finder.
where can i buy, how do i put mount on telescope without drilling etc.
There are 2 at MyAstro - one you can use double sided adhesive :

http://www.myastroshop.com.au/produc...sp?id=MAS-268b

http://www.myastroshop.com.au/produc...asp?id=MAS-268

Cheers
Reply With Quote
  #6  
Old 17-06-2008, 08:42 PM
caleb
Registered User

caleb is offline
 
Join Date: Dec 2007
Location: gosford, australia
Posts: 206
astersik, that is exactly what i need. but $60 is alot of money. i woult have thought they were much cheaper than that. i am sure it is of excelent quality though.
Reply With Quote
  #7  
Old 17-06-2008, 08:48 PM
erick's Avatar
erick (Eric)
Starcatcher

erick is offline
 
Join Date: Dec 2006
Location: Gerringong
Posts: 8,548
Yep, they have always been expensive to me. And when it is cold, the laser gets too cold to operate efficiently (it's not the batteries - its the laser itself).

When I get the time I'll put up an article on my extremely low cost, no frills, no moving parts laser pointing system in which you get to keep the laser warm.
Reply With Quote
  #8  
Old 17-06-2008, 08:57 PM
MrB's Avatar
MrB (Simon)
Old Man Yells at Cloud

MrB is offline
 
Join Date: Jan 2007
Location: Rockingham WA
Posts: 3,435
Interesting, I had read somewhere that some research labs had been supercooling laser diodes to shift their wavelength down(shorter), no mention of reduced output power, not saying your wrong tho, just that it's an interesting observation.
Have you tried it at the same temp with an alternative power source?

Edit: Nevermind, I just thought of a possible explaination why reduced output might occur.
Reply With Quote
  #9  
Old 17-06-2008, 11:11 PM
erick's Avatar
erick (Eric)
Starcatcher

erick is offline
 
Join Date: Dec 2006
Location: Gerringong
Posts: 8,548
This in an FAQ on a site selling green lasers:-

"I've heard that green lasers don't work well in the cold — does Jasper have this problem?
All green lasers are sensitive to cold temperatures for a couple of reasons. The laser circuit itself is not as efficient and batteries deliver lower voltage at cold temperatures. Jasper's lithium battery works better in cold temperatures than do standard alkaline batteries.
Jasper's APC further minimizes this problem by applying maximum electrical power when the laser output is dim or non-existent. As the laser warms and becomes more efficient, electrical power is reduced.
Lasers without APC deliver a constant amount of electrical power without regard to output power. While such a setting is sufficient at warm temperatures it isn't enough in a cold environment.
Even Jasper will not start in extremely cold temperatures. You can overcome that problem by warming Jasper in your hand for a minute or two before using it on cold nights. Once Jasper begins operation, it will usually generate enough heat to keep itself warm."



Looking at the quoted "working temperature" for the multitude of green handheld lasers some say lower limit of 20degC, some 10degC, some 0degC??
Reply With Quote
  #10  
Old 17-06-2008, 11:19 PM
madtuna's Avatar
madtuna (Steve)
an overactive imagination

madtuna is offline
 
Join Date: Dec 2007
Location: Erlistoun WA
Posts: 592
That may be a problem for a mounted laser, but for hand held I just keep it in my pocket and never have a problem
Reply With Quote
  #11  
Old 18-06-2008, 12:00 AM
erick's Avatar
erick (Eric)
Starcatcher

erick is offline
 
Join Date: Dec 2006
Location: Gerringong
Posts: 8,548
Indeed, that is the solution in cold weather. Now one then needs a quick install mount arrangement to facilitate the fact that the laser lives mostly in a nice warm pocket.

In fact, I think it's a good idea, in the new regime re lasers, to keep that laser secure in ones pocket most of the time.
Reply With Quote
  #12  
Old 18-06-2008, 12:04 AM
madtuna's Avatar
madtuna (Steve)
an overactive imagination

madtuna is offline
 
Join Date: Dec 2007
Location: Erlistoun WA
Posts: 592
That's why god invented the bum crack and the pocket on the front of daddy undies
Reply With Quote
  #13  
Old 18-06-2008, 12:39 AM
Jeff's Avatar
Jeff
Starry Eyed

Jeff is offline
 
Join Date: Dec 2007
Location: Wonga Park
Posts: 692
Hi Caleb,

You can cheaply mount a laser in the using a small (useless) finder scope. I purchased a cheap 5x24mm finder/mount on eBay for under $10 delivered, then shoved the laser up my ..... finder tube with a bit of cloth tape added to make it a snug fit.

If unable to find a suitable finder bracket, I probably would have made something out of wood and well prepared chewing gum.

Hope this helps.

Cheers,
Jeff
Reply With Quote
  #14  
Old 18-06-2008, 07:51 AM
OneOfOne's Avatar
OneOfOne (Trevor)
Meteor & fossil collector

OneOfOne is offline
 
Join Date: Jul 2005
Location: Bentleigh
Posts: 1,386
Quote:
Originally Posted by erick View Post
Yep, they have always been expensive to me. And when it is cold, the laser gets too cold to operate efficiently (it's not the batteries - its the laser itself).

When I get the time I'll put up an article on my extremely low cost, no frills, no moving parts laser pointing system in which you get to keep the laser warm.
I cut my laser open with a hacksaw so I could connect directly to the battery terminals and then connected it to a voltage regulator circuit set to output 3.00V from 4xAA cells. If I put it in the freezer, it outputs 2.96V. The problem is the laser doesn't work even in the fridge, so yes, that confirms that it is the laser diode and not the batteries at all.

My next thought is to put a small resistor inside the laser tube and run a couple of watts directly from the batteries to keep it warm, with a switch to turn it on when needed...or maybe a dew strap wrapped around it!

But normally I only use the laser for alignment at setup time. At public viewings I use the one in my pocket.
Reply With Quote
  #15  
Old 18-06-2008, 09:47 PM
MrB's Avatar
MrB (Simon)
Old Man Yells at Cloud

MrB is offline
 
Join Date: Jan 2007
Location: Rockingham WA
Posts: 3,435
Yes it's the laser, I made the comment above before I remembered you guys use green lasers.
I figured there may be a problem with the shift in wavelength of the diode being pushed outside the operating bandwidth of the frequency doubling optical crystals used in these.
While this is true, after doing a bit of research I found it's mainly a problem with just one component. While all other components would be quite happy at lower temps(including one of the crystals (Nd:YAG)) and likely to be more efficient, one crystal(the freq doubler (KTP)) is happier the warmer it is (40-50c).... room temp happens to be a handy compromise for all components.

If anyone is interested in learning more, check out Sam's Laser FAQ - a massive website, the link tho is directed to a page about a homemade green laser diode with mention about temperature wavelength tuning, KTP heaters etc.

Thread hijack over....(sorry!)

Last edited by MrB; 18-06-2008 at 10:09 PM.
Reply With Quote
  #16  
Old 18-06-2008, 10:10 PM
erick's Avatar
erick (Eric)
Starcatcher

erick is offline
 
Join Date: Dec 2006
Location: Gerringong
Posts: 8,548
Thanks for the info, MrB

Surely there is a market for an astronomical version with a small heater on that KTP crystal. Would the battery drain be too great to get it up 10 deg C?
Reply With Quote
  #17  
Old 20-06-2008, 01:35 AM
MrB's Avatar
MrB (Simon)
Old Man Yells at Cloud

MrB is offline
 
Join Date: Jan 2007
Location: Rockingham WA
Posts: 3,435
Maybe, maybe not - depends what size cells are used, if they're the little button cells, then yeah too much drain, but if AAA or larger there would be plenty 'nuff grunt for ?? hours of run time with a resistor or two as heaters.
Reply With Quote
  #18  
Old 20-06-2008, 02:40 AM
mabsj2's Avatar
mabsj2
Joash

mabsj2 is offline
 
Join Date: Mar 2008
Location: some where far away.
Posts: 58
try ebay. i am sure there are such stuff for sale..
Reply With Quote
  #19  
Old 20-06-2008, 08:03 AM
astronut's Avatar
astronut (John)
2'sCompany3's a StarParty

astronut is offline
 
Join Date: Oct 2005
Location: Eagle Vale
Posts: 1,251
Caleb,
This is how I mounted my laser. I've run a lead from my power supply to a heater wrapped around the laser.
This helps to keep the unit operating in cold conditions.
I also recommend that you use Lithium batteries to run the laser.
I purchased the mount from Scopestuff.
Attached Thumbnails
Click for full-size image (laser.jpg)
36.0 KB40 views

Last edited by astronut; 20-06-2008 at 08:56 AM.
Reply With Quote
  #20  
Old 21-06-2008, 04:46 PM
caleb
Registered User

caleb is offline
 
Join Date: Dec 2007
Location: gosford, australia
Posts: 206
if i have my laser on and walk outside it will dim. usualy diming to nothing. and it usualy takes a few mins to warm up and it sudenly goes bright green.

and.. i havn't found anything for a mount yet, still looking.
Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 04:17 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Advertisement
Astrophotography Prize
Advertisement
Bintel
Advertisement